1. Field of the Invention
The present invention is directed to a vaporizer carousel for an anaesthetic apparatus of the type having a holder for at least one vaporizer, a gas conduit system in the holder, and a gas supplied device which the holder is rotatably arranged, with the gas supply device having respective connections for carrying gas to and from the gas conduit system.
2. Description of the Prior Art
A vaporizer carousel with a rotating holder for three vaporizers is described in U.S. Pat. No. 4,058,120. Each vaporizer is equipped with one gas inlet and one gas outlet (i.e. a separate pair of connectors for each vaporizer). The holder is placed on a gas manifold provided with one gas inlet and one gas outlet. The inlet and the outlet are arranged so they can be connected in turn to a respective pair of vaporizer connectors when the holder is rotated. Only one vaporizer at a time can therefore be connected to the gas manifold's gas inlet and gas outlet to deliver anaesthetic to a gas flowing through the vaporizer. For each connection position for the holder, i.e. relative to each vaporizer's pair of connectors, the position of the holder is fixed in relation to the gas manifold by a lock.
An inhalation apparatus with four bottles for liquids rotationally arranged on a hollow rod is described in German Patentschrift 255,258. Radial gas channels are arranged in the rod so a gas can be delivered to one bottle at a time. The bottle to receive gas is rotated to a position at which it connects to the radial gas channels. Bottles are locked in this position by a spring-loaded pin.
With these devices, gas flow must be turned off whenever a new vaporizer or bottle is to be connected, the rotating part must be unlocked and turned to a new exact position for the vaporizer or bottle to be connected, the new vaporizer or bottle must be locked in the new position and the gas flow must be turned back on. With vaporizer carousels, this means that residual anaesthetic gas in gas conduits could escape into the operating room when a vaporizer or bottle is disconnected. The mixing of two anaesthetic agents when a new vaporizer is activated also poses a major risk, since some "old" anaesthetic gas always remains in conduits leading from the vaporizer carousel. This situation should be avoided completely, since the effect of such anaesthetic mixing on the patient is unknown.
Moreover, the vaporizer carousel/inhalation apparatus cannot be rotated once a vaporizer/liquid bottle has been activated. This restricts the operator's freedom of movement when using the system. In modern operating rooms employing a large amount of technical equipment connected to the patient, space near the patient can be very cramped during surgery in certain situations. It would therefore be advantageous if e.g. the anaesthesiologist was not forced to sit at a particular location the entire time in order to exercise control over the patient and the anaesthesia machine, but be able to move about more freely around the anaesthesia equipment and patient, with no loss of control.